Japanese Patent Application Publication No. 2012-146760 discloses a semiconductor device using an insulated substrate. The insulated substrate is a substrate mainly used in a circuit for a power system and has a structure in which a metal layer constituted of copper, aluminum, or the like is disposed on each of both faces of an insulator layer constituted of ceramic, for example. A semiconductor device includes the insulated substrate and a plurality of semiconductor elements mounted on the metal layer disposed on one face of the insulated substrate.